Paul Green is a Philadelphia-based former musician and current capo di tutti capi of Rock School, a music camp of the sort Jack Black founds in the conclusion of the Richard Linklater comedy School of Rock. Green is irrepressible, the kind of guy whose mouth is in gear way before his brain. He’s full bore American — hilarious, at least from this side of the screen. His drive and honesty endears him to a collection of self-admitted misfits, kids from the ages of nine to 17, most of who have big dreams of making a life in music. The film follows the kids, both talented and not so much, as they stumble through shows playing ’80s tunes (“Don’t make mistakes! Not on ‘Rebel Yell!’” screams Green) and Black Sabbath (“Do you love Dio? Do you love Satan?”), concluding with a triumphant gig at a German Frank Zappa festival. The DVD is stocked with deleted scenes further emphasizing Green’s special brand of nuttiness. Inspiring, in a weird way.